Electric switch



Sept 12, 1944- c. F. RoBBlNs 2,357,972

ELECTRIC SWITCH Filed Aug. 1. 1942 2 sheets-snm 2 d a fo? .54 ab 33\, J\ L56 59 54 34 34C 555 ya? a7 M 43 w-@Qwm Patented Sept. 12, 1944 ELECTRIC SWITCH Clyde F. Robbins, Milwaukee, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application Aug-ust 1, 1942, Serial No. 453,221

('Cl. 20D-5) 12 Claims.

This invention relates to improvements in electric switches. The invention relates more particularly to a combined latching and releasing attachment for a pushbutton switch of the reciprocating contactor type.

A primary object of the invention is to provide a combined latching and releasing device attachable as a unit to a pushbutton switch of known form, to thereby provide a two-button switch unit of the character herein contemplated.

Another object is to provide an insulation deadfront for a two-button, latched switch mechanism of the aforementioned character.

Another object is to provide a two-button switch mechanism of the aforementioned character affording a predetermined standard spacing of the pushbuttons, to provide for interchangeability thereof with other pushbutton switch mechanisms in a preformed mounting panel or casing.

Another object is to provide two-button, latcned switch mechanisms adapted for either base mounting or so-called one-hole mounting.

Another object is to provide for substitution of the latching attachment herein contemplated for the usual adapter member of the pushbutton switch.

Another object is to provide for rigid securement of the latching attachment to the insulating base of the switch by use of the mounting screws usually employed with the latter.

Another object is to provide an extremely simple form of latch and a correspondingly simple form of bell-crank operating lever interposed between the same and the added pushbutton.

Another object is to provide a novel form of latch mechanism which acts to retain one or the other of the pushbuttons in depressed position to properly indicate the condition of the circuit or circuits controlled by the switch.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate certain embodiments of the invention which will now be described, it being understood that the embodiments illustrated are susceptible of modification in respect of certain structural details thereof without departing from the spirit of my invention or the scope of the appended claims.

In the drawings, Figure 1 is a top plan view of a base mounted pushbutton switch having my improved latching and releasing attachment associated therewith.

Fig. 2 is a side elevational view of the switch mechanism shown in Fig. l, the pushbutton switch being shown in its upper or unlatched position, and a fragment of the panel, to which the unit is base mounted, being shown in section.

Fig. 3 is a sectional view, on the line 3-3 of Fig. l, but showing the pushbutton switch in its latched down position; and indicating plates being shown attached to the front panel or cover member.

Fig. 4 is a detail perspective View, in separated relation, of the slidable latch member and the bell-crank operating lever to be associated therewith.

Fig. 5 is a bottom plan view of the device shown in Figs. 1 to 4, the switch pushbutton and the securing screws being shown in section, and the insulating base and its associated parts being omitted for purposes of illustration, the parts of the device being shown in the relative positions thereof illustrated in Fig. 3.

Fig. 6 is a top plan view of a devicequite similar to that shown in Figs. l to 5, but modified to pro vide the so-called one-hole type or' mounting for the unit, a pair of indicating or legend plates being shown in assembled position, the wiring terminals being omitted, and

Fig. 7 is a sectional view, on the line 'l of Fig. 6.

Referring rst to that form of my invention shown in Figs. l to 5, the numeral it designates a member molded from a suitable insulating material, the same preferably being hot molded from a material such as Bakelite Member i includes a relatively thin, flat portion IDE, which is of substantially rectangular contour at one end lllb, and at its other end merges into the substantially cylindrical upward extension lila, as shown at 10d, llle (Figs. 1 and 2). Extension Il]c is provided with a passage therethrough of circular form in transverse cross section, as shown at IOf (Figs. 1 and 3) to provide reciprocating clearance for the cylindrical pushbutton i i, the latter being provided adjacent its lower end with a peripheral flange l la, which is adapted to engage the iiat lower face i0@ or member l0 to limit the degree of upward movement of pushbutton i l.

Extension i@ is preferably provided at its upper end with a relatively short cylindrical portion i011, of reduced diameter, which is adapted to l'it into a circular opening i2a of corresponding size within a front panel or cover member l2, so that the upper end of portion lh is substantially flush with the outer surface of panel l2, as shown in Fig. 3; the substantially annular shoulder 101 (Figs. 1 and 2) being adapted to seat against, or being engaged by, the inner surface of panel l2.

Said annular shoulder ibi is preferably pro`1 vided with a pair of diametrically opposed notches or recesses i6! and ilik; and a notch i6* at one end of member i0, and spaced at an angle of ninety degreesfrom the notches itil, it* (Figs. 1 to 3). Shoulder i()1 is also preferably provided at a point diametrically opposite to notch id with a relatively small substantially cylindrical recess idf", the functions of recess im and of notches iti, itk and itl being hereinafter described.

Recess ibm is' in par-t located within a rib or diaphragm i6 extending upwardly from the fiat portion it to the plane of shoulder il, which diaphragm is likewise integral with another cylindrical extension it", which is of the same height as, and parallel with, extension i. Extension i is provided with a. passage iiiP of circular form in transverse cross section to provide reciprocating clearance for the pushbutton i3. Pushbutton i3 is provided adjacent to its lower end with a peripheral flange portion i3, which corresponds with the flange ii of pushbutton ii; and pushbutton i3 may be identical in other respects with pushbutton ii, except that pushbutton i3 is provided at a predetermined point in its length with an upwardly facing shoulder iib (Fig. 3), which is preferably provided by an annular groove itlc milled or otherwise formed in the periphery of pushbutton I3. The pushbuttons ii and i3 are of the same form and dimensions as the pushbuttons of normal length employed with base mounted switches of the character disclosed in my prior application, Serial No. 449,756, led July 4, 1942. Thus pushbutton i3 is provided with a recess i3cl (Figs. 3 and 5) to accommodate the extension it formed upon the contactor-carrying plunger Hi (see Fig. 3), extension ili being formedito accommodate the spring ring shown in dotted lines at 30 to provide a frictional connection between said parts. Similarly, pushbutton il is provided with a recess iid to accommodate the correspondingly shaped portion i5 of a machined metal stud i5 (Figs. 2, 3 and 5). As shown in Fig. 3, Stud i5 is provided with a reduced upper end portion i 5b which facilitates forcible insertion of a spring ring i5 into a peripheral groove formed between said reduced end and portion i5, whereby a frictional connection between pushbutton Ii and stud i5 is provided. The contactar-carrying plunger id is biased toward its upper extreme position by the conical compression spring d3 (Figs. 3 and 7).

As shown in Figs. 2 and 5, insulating member i is preferably provided in its flat lower surface with a pair of substantially rectangular recesses il)q and itil' to respectively accommodate the upper ends of lateral extensions formed upon the insulating base il of the switch, one of such lateral extensions being shown at i'l in Fig. 2; whereby the iiat lower surface of member i0 is adapted to seat against the upper end of base i7 (see Fig. 2). Moreover, I prefer to provide member in with lateral extensions its arie im, within the areas of whichthe aforementioned recesses i011 and itil are formed, to fully overlie the respective upper ends of the lateral extensions of base i7. Extensions IUS and illt are provided with openings, alined with the openings in base I7, to provide clearance for the shanks of bolts I8, I8, whose threaded lower ends take into tapped openings in a panel i9 (Fig. 2) or other suitable support, the heads of bolts i8 being seated against the upper surfaces of extensions i0* and asszera itt, preferably with interposed lockwashers i@ (see Fig. 2).

The cylindrical extension i of member i@ is preferably provided at diametrically 4opposite points with arcuate cut away portions or recesses iii and it to accommodate or provide clearance for the heads of screws i8. Extension i is also preferably provided with an upwardly opening notch or recess it (alined with notch iiil on extension it?) and with a cylindrical recess it, alined with and corresponding to recess iiim.

Member i@ is provided in its lower surface with a groove illy (Figs. 3 and 5) of inverted channel form, said groove communicating at opposite ends with the respective pushbutton passages if and idp; a relatively narrower groove idf (Fig. 3) opening to one end portion of groove iiiy and to pushbutton vpassage idf. Extending downwardly from and formed integrally with the fiat lower surface of member i6 are a pair of lugs, which are designated by numerals 2@ and 2 i, said lugs having openings 2G and 2 i formed therein to accommodate a pin 22, whose head is shown at 22e in Fig. 5, and whose shank end the relative positions on the flat lower surface of member iB, best illustrated in Fig. 5.

A iiat, punched sheet metal latch member 23 is positioned within groove lily for sliding movement relatively thereto, member 23 having a concave edge 23 at one end thereof to fit within groove i3 and to overlap the shoulder isb formed by said groove, when pushbutton i3 is depressed to the position thereof shown in Fig. 3; and said edge 23a being adapted to abut against the periphery of the lower portion of pushbutton i3 when the latter is in its upper extreme position. for a purpose hereinafter described. The member 23 is provided with an opposite end edge 23h of concave form to provide clearance between said member and the periphery of pushbutton i i upon depression of the latter. Member 23 is provided adjacent the edge 23h with a relatively narrow rectangular opening 23e.

A punched and stamped sheet metal lever member 2li is provided (see Fig. 4). Member 2d is in .the form of a bell-crank lever, the same comprising a U-shaped portion having a pair of spaced parallel arms 2da and 25h, and a connecting portion 24C. Portion 2lia projects upwardly to form the other arm of the bell-crank lever, as shown at 24d, and said arm has a reduced upper end portion 2de which loosely fits into the aforementioned opening 23 in latch member 23(Figs. 3 and 4). Arms li and 26h are provided with alined openings (one of which is shown at Zrif in Fig. 4) to accommodate the pin 22 which pivotally supports lever 2H; and alined openings Zi and 26h, which are adapted to be alined with a transverse opening or passage i5c (Fig. 3) in member i5 to accommodate the shank of a pin 25, the head of which is shown at 25a (Figs. 2 and 5).

During assembly of pin 22 with respect to the parts, as shown in Figs. 3 and 5, said pin is passed through the coiled portion of a spring 26 (Figs. 3 and 5). The aforementioned lug 20 is provided on its inner side (adjacent to and integral with the flat lower surface of member i) with a reinforcement or iillet 20h, and spring 26 is provided with an arm or straight end portion 26 which is adapted to seat or press against one side of said illlet to afford the desired degree o! upward blasupon the other end portion 2Gb of spring 28; said portion 26b having an upwardly bent end 26 (see Fig. 3) which penetrates an opening yprovided in the projecting shank end of pin 25, to restrain the latter against endwise displacement. The arrangement of parts and the bias of spring 26 is such that upon depression of pushbutton I3 to the position thereof shown in Fig. 3, the latch member 23 is freed to move toward the left into groove I3, through the action of bell-crank lever 2l, as an incident to the upward bias upon pin 25, with consequent upper extreme positioning of member I5 and pushbutton II attached thereto. Conversely, upon manual depression of pushbutton II against the bias of spring 26, the bell-crank lever 2l will act t0 Withdraw latch member 23 from groove I3, thus permitting pushbutton I3 to move to its normal upper extreme position (as shown in Fig. 2.)

under the normal spring bias of plunger I4, as described in detail in my prior application, Serial No. 449,756.

As best illustrated in Fig. 3, the aforementioned groove IIJz affords oscillatory clearance for the reduced end 24e of bell crank lever 24. As shown in Fig. 5, a llet 2|b is provided between the outer side of lug 2| and the flat lower surface of member IIJ, to reinforce or strengthen said lug.

As will be apparent from consideration cf Fig. 3, when pushbutton II is depressed, with consequent release of pushbutton I3 to its upper extreme position, the lower cylindrical portion of pushbutton I3 will act as an abutment for the left-hand end of latch member 23, thus locking pushbutton I I against movement to its upper extreme position under the bias of spring 26. It follows that each button when depressed is latched in depressed position, and can only be released to its normal upper extreme position as an incident to depression of the other button.

As will be apparent to those skilled in the art, in the light of the disclosure in said application, Serial No. 449,756, the insulating base Il may have attached thereto from one to four pairs of combined stationary contact and terminal members 3i and/or 32 and from one to four bridging contactors 42 for cooperation therewith (Figs. 2, 3 and 7). Where only upper stationary contacts are employed, the pushbutton I3 when depressed will cause interruption of the circuit or circuits through all of said contacts, such circuit interrupting condition of the switch being maintained by the latch member 23 pending subsequent depression of pushbutton I I.

Where only lower stationary contacts are employed, the circuit or circuits will be completed upon depression of pushbutton I3, and will be maintained closed by the action of the latch member 23 pending subsequent depression of pushbutton lI. The functioning of the switch where both upper and lower contacts are employed is believed to be obvious from the foregoing description.

As shown in Figs. 1, 2 and 3, extension I0 is provided with an upwardly projecting portion 2'I of reduced diameter, thus providing a substantially annular shoulder 2'Ia which seats against, or is engaged by, the inner surface oi panel I2. As shown in Fig. 3, portion 21 nts into an opening I2b provided in panel I2, so that the outer end of said extension is substantially flush with the outer surface of said panel. In

the particular arrangement shown in Fig. 3, It may be assumed that the device is mounted with the pushbuttons II and I3 spaced horizontally a predetermined distance from each other, as distinguished from a vertical arrangement of the pushbuttons (see Fig. 6)

Said pushbuttons II and I3 may have suitable legends, such as Stop, Start or Forwardf Reverse," etc., applied thereto respectively by molding into the upper ends thereof the letters of such legends, such lettering preferably being depressed and the depressed letters filled with an enamel or similar material of a contrasting color, such as white. However, when plain pushbuttons are employed, the indicating legends may be properly associated therewith, as by employing metal plates 28 and 29 (Fig. 3), which have circular openings 28B and 29a to provide clearance for the buttons I3 and Il, said plates having rectangular portions at one end of each of the same (not shown in Fig. 3) to have the desired legends imprinted thereon or otherwise applied thereto. Plates 28 and 2S each preferably have a pair of relatively small circular openings formed therein, as shown at 28h, 28c and 29h, 29, said openings being alined with corresponding openings in panel I2 (Fig. 3) to accommodate with a drive t the Shanks of drive screws 30,`

whereby said plates are secured in position. As shown in Fig. 3, the recesses I 0m, I 0X and notches 01, IIlW afford clearance for the shank ends of screws 30.

In the event that the pushbuttons II and I3 are to be arranged in vertical alinement with each other, the plates 28 and 29 will be positioned at rotary angles displaced ninety degrees from the positions thereof shown in Fig. 3, the panel I2 in such an arrangement having other openings to accommodate with a drive lit the Shanks of drive screws 33. Under these conditions notches till, Ik and recesses lil, IIlV will serve to provide clearance for the Shanks of screws 33.

The combined Contact and terminal members (Fig. 2) may be of the so-called right-hand form 3l and the sci-called left-hand form 32, or all of the combined contact and terminal members may be of identical form, if the terminal portions of alternate members are permitted to extend laterally beyond the contour of base Il', as set forth in said application, Serial No. 449,756. Each of the members 3i and 32 has a contact tip 4I of silver or the like attached thereto (Figs. 2, 3 and 7).

The device of Figs. 6 and 7 is in many respects identical with that aforedescribed, and corresponding parts have been designated by like numerals of reference. Moreover, the molded insulating member 33 is generally similar, in contour and dimensions, to the member I0 aforedescribed, and one of the two die members (not shown) employed to produce member Ill may likewise be employed in the production of member 33. However, a different core member is utilized in the formation of member 33, to produce the passages 33X and 33y which are internally threaded (preferably by the molding operation) to receive the externally threaded end portions 343, 34B' of like metal bushings 34, 34, whose relatively large upper end portions 34h, 34b provide downwardly facing annular clamping shoulders 34C, 34C, to provide the so-called one-hole mounting type of attachment of member 33 to a front supporting panel. Panel 35 is provided with openings 35, 35h to accommodate the Shanks till of bushings Sli. The. upper end portions Zilli of bush- I ings 3d are preferably vertically milled or otherwise roughened peripherally, as shown at Bald,

Fig. 6, to facilitate tightening thereof manually or otherwise. The portion 33h of member 33 corresponds in form and dimensions to portion lilb of member lo, and the cylindrical extensions 3 and 33 have external dimensions corresponding to those of extensions Ille and l o member it. Due to the relatively large diameter of the passages 33X and 33Y in memberl there are no upward extensions of reduced diameter to lt within the openings 35a and 35h of panel 3b. However, the annular surfaces 33d and 83e (Fig.

7) are adapted to seat against the inner surface second plate 3l may be identical in form with plate 36, plate 37, however, having a diiierent desired legend applied thereto. The lug 37B on plate 3l extends downwardly through an 'opening in panel 35 and is adapted to clear the exterior of extension 33 of member 33. Plate 3l is therefore also positively restrained against rotary displacement.

Because of the height of portions 3G of bushings d the pushbuttons 39 and 39 are made substantially longer than the corresponding pushbuttons l l and i3 of the device of Figs. l. to 5. The pushbutton 39 is provided at a predetermined distance from the lower end thereof with aperipheral groove 39B, which provides the upwardly facing shoulder 39il which is engaged by latch member 23, upon depression of pushbutton 39, to retain said pushbutton in depressed position pending subsequent depression of pushbutton 38.

The laterally extending portions 33B and 33t of member 33 correspond with portions lli and lili of member l0. However, said portions 33H and 33i are respectively provided with tapped openings 33u. 33V (Fig. 6) for cooperation with the shanks of a pair of bolts im, lll, the heads of which (not shown) are positioned within the countersunk recesses in the lower surface of base ll, in a manner similar to the one-hole mounting device disclosed in said application, Serial No. 449,756. y

The device of Figs. 6 and 'I is'adapted to operate in the same manner, and to perform the same functions, as the device of Figs. 1 to 5.

I claim:

l. In combination, a pushbutton switch of the reciprocating contactor type comprising, a molded insulating base having a recess, a molded insulating plunger slidable within said recess, at least one pair of stationary contacts positioned within said recess and alined with each other transversely of said base, at least one contactor carried by said plunger and movable by the latter into and out of bridging engagement with said contacts` a coiled compression spring engaged with the lower end-of said plunger to bias the latter and said contactor outwardly to a asevera given normal position relatively to said contacts, a pushbutton attached to the outer end of said plunger and movable therewith, said pushbutton having an exterior outwardly facing shoulder formed 'thereon intermediate the length thereof,

siidable latch member, spring means icr 'normally biasing said latch member to a position wherein it overlies said shoulder as an incident to a given degree ci inward movement of said pushbutton, to thereby latch said contactor out ci seid normal position thereof, and means comprising second pushbutton reciprccable in a plane parallel to said drst pushbutton and having permanent driving connection with said latch member to provide ror release or said first pushbutton to its normal biased position as an incident to depression or" said second pushbutton.

2. ln combination, e, pushbutton switch oi the reciprocating contactor type comprising, a molded insulating base having a recess, a molded insulating plunger siidable within said recess, at least one pair of stationary contacts positioned within said recess and alined with each other transversely of said base, at least one contactor carried by said plunger and movabie'by the latter into and out of bridging engagement with said contacts, a coiled compression spring engaged with the lower end of said plunger to bias the latter and said contactor outwardly to a given normal position relatively to said contacts, a pushbutton attached to the outer end of said plunger and movable therewith, said pushbutton lhaving an exterior outwardly facing shoulder formed thereon intermediate the length thereof, a slidable latch member, spring means for normally biasing said latch member to aposition wherein it overlies said shoulder as an incident to a given degree of inward movement of said pushbutton, to thereby latch said contactor out of said normal position thereof, means comprising a second pushbutton reciprocable in a plane parallel to said iirst pushbutton and having a permanent driving connection with said latch member to provide for movement of the latter, against its bias, in a direction to effect release of said first pushbutton to its normal biased position as an incident to a given degree of depression of said second pushbutton, and said rst pushbutton when released cooperating with said latch member to retain said second pushbutton in a depressed position pending subsequent depression of said rst pushbutton.

3. In combination, a pushbutton switch of the reciprocating contactor type comprising, a molded insulating base having a recess, a molded insulating plunger slidable within said recess, at least one pair of stationary contacts positioned within said recess and alined with each other transversely of said base, at least one contactor carried by said plunger and movable by the latter into and out of bridging engagement with said contacts, a coiled compression spring interposed between the bottom wall of said recess and said plunger to bias the latter and said contactor outwardly to a given normal position relatively to said contacts, a pushbutton attached to the outer end of said plunger and movable therewith, said bushbutton having an exterior outwardly facing shoulder formed thereon intermediate the length thereof, a slidable latch meml ber, spring means for normally biasing said latch member to aposition wherein it overlies said shoulder as an incident to a given degree of inward movement of said pushbutton, to thereby latch said contactor out of said normal position thereof, means comprising a second pushbutton reciprocable in a plane parallel to said first pushbutton and having a permanent driving connection with said latch member, the biasing spring of said latch also normally tending to move said second pushbutton to its outer extreme position, said second pushbutton when manually depressed -being adapted to effect movement of said latch to thereby release said first pushbutton for return of the latter to said normal position thereof, and said iirst pushbutton when so released coacting with said latch member to retain said second pushbutton in its depressed position, to thereby indicate the circuit controlling condition of the switch.

4. As an article of manufacture, a latching attachment for a pushbutton switch of the reciprocating contacter type, said attachment comprising an insulating member having an opening formed therein to provide reciprocating clearance for the spring-biased pushbutton of the switch, said member having a second opening formed therein in spaced parallel relation to said rst opening, said member having a groove formed in the substantially fiat lower surface thereof and communicating with said openings, a flat, punched sheet metal plate slidably seated flatwise within said groove in a substantially fiush relationship to said lower surface, said insulating member having a pair of perforated lugs formed integrally therewith-and extending downwardly therefrom on opposite sides of said groove, a pivot pin supported by said perforated lugs, a bell-crank lever pivotally supported by said pin, said metal plate having an opening formed therein adjacent one end thereof, one arm of said lever having its free end engaging the walls of said plate opening to provide a driving connection ybetween said parts, a second pushbutton reciprocaole within said second opening in said member, the other arm of said lever having a pivotal connection with said second pushbutton, and spring means for biasing said second pushbutton toward its outer extreme position, whereby said plate is biased into the area of said first mentioned opening.

,es an article of manufacture, a latching attachment for a pushbutton switch of the recipro-l eating contacter type, said attachment comprising an insulating member having an opening formed therein to provide reciprocating clearance for the spring-biased pushbutton of the switch, said member having a second opem'ng formed therein in spaced parallel relation to said first opening, said member having a groove formed in the substantially at lower surface thereof and communicating with said openings, a flat, punched sheet metal plate slidably seated flatwise within said groove in a substantially rlush relationship to said lower surface, said insulating member having a pair of perforated lugs formed integrally therewith and extending downwardly therefrom on opposite sides of said groove, a pivot pin supported by said perforated lugs, a bell-crank lever pivotally supported Iby said pin, said metal plate having an opening formed therein adjacent one end thereof, one arm of said lever having its freeend engaging the walls of said plate opening to provide a driving connection between said parts, a second pushbutton reciprocable within said second opening in said member, the other arm of said lever having a pivotal connection with said second pushbutton, spring means for biasing said second pushbutton toward its outer extreme position, whereby said plate is biased into the area of said first mentioned opening, and said plate when freed to move under its bias being adapted to overlie an outwardly facing shoulder on said switch pushbutton, as an incident to depression of the latter, whereby said switch pushbutton is retained in its depressed position.

6. As an article of manufacture, a' latching attachment for a pushbutton switch of the reciprocating contactor type, said attachment comprising an insulating member having an opening formed therein to provide reciprocating clearance for the spring-biased pushbutton of the switch, said member having a second opening formed therein in spaced parallel relation to said first opening, said member having a groove formed in the substantially flat lower surface thereof and communicating with said openings, av flat, punched sheet metal plate slidably seated atwise within said groove in a substantially flush relationship to said lower surface, said insulating member having a pair of perforated lugs formed integrally therewith and extending downwardly therefrom on opposite sides of said groove, a pivot pin supported by said perforated lugs, a bell-crank lever pivotally supported by said pin, said metal plate having an opening formed therein adjacent one end thereof, one arm of said lever having its free end engaging the walls of said plate opening to provide a driving connection between said parts, a second pushbutton reciprocable within said second opening in said member, the other arm of said lever having a pivotal connection with said second pushbutton,

spring means for biasing said second pushbutton toward its outer extreme position, whereby said plate is biased into the area of said rst mentioned opening, said plate when freed 'to move under its bias being 'adapted to overlie an outwardly facing shoulder on said switch pushbutton, as an incident to depression of the latter, whereby said switch pushbutton is retained in its depressed position, and said second pushbutton when depressed being adapted to effect withdrawal of said plate from said rst mentioned opening to provide for normal positioning of said. .first pushbutton under the iniiuence of its springbias.

7, in combination, a pushbutton switch of the reciprocating contacter type comprising, a molded insulating base having a recess, a molded insulating plunger slidable within said recess, at least one pair of upper stationary contacts and one pair of lower stationary contacts positioned within said recess, the contacts of each pair being alined with each other transversely of said base, at least one upper contactor and one lower contactor carried by said plunger and selectively movable by the latter into and out of bridging engagement with the respective upper and lower pairs of contacts, a spring biasing said plunger outwardly whereby the upper contactor is engaged with said upper pair of contacts, a pushbutton attached to the outer end of said plunger' and movable therewith, said pushbutton having a peripheral groove formed therein at a predetermined point above the lower end thereof to provide an exterior outwardly facing shoulder, a punched sheet metal latch member bodily slidable flatwise into and out of said groove, spring means for normally biasing said latch member toward a position wherein it will overlie said shoulder upon a given degree of inward movement of said pushbutton to thereby latch said upper contactor out of engagement with its associated contacts and said lower contactor in engagement with its associated contacts, and means comprising a second pushbutton reciprocable in a line parallel to said rst pushbutton and having a permanent driving connection with said latch member, said second pushbutton when depressed being adapted to eiect release of said rst pushbutton, whereby said plunger is free to move under its bias to effect re-engagement of said upper contactor with its associated contacts and disengagement of said lower contactor from its associated contacts.

8. In combination, a pushbutton switch of the reciprocating contacter type comprising, a

molded insulating base having a recess, a, molded insulating plunger slidable within saidrecess, at least one pair of upper stationary contacts and one pair of lower stationary contacts positioned 4 within said recess, the contacts of each pair being alined with each other transversely of said base,

4 ripheral groove formed therein at a predetermined point above the lower end thereof to provide an exterior outwardly facing shoulder, a latch member slidable into and out of said groove, spring means for normally biasing said latch member toward a position wherein it will overlie .said shoulder upon a given degree of inward movement of said pushbutton to thereby latch said upper contactor out of engagement with its associated contacts and said lower contactor in engagement with its associated contacts, means comprising a second pushbutton reciprocable in a line parallel to said rst pushbutton and having a permanent driving connection with said latch member, said second pushbutton when depressed being adapted to effect release of said first pushbutton, whereby said plunger is free to move underits bias to effect re-engagement of said upper contactor with its associated contacts and disengagement of said lower contactor from its associated contacts, and said iirst pushbutton when released coacting with said latch member to retain said second pushbutton in a depressed position pending subsequent depression of said rst pushbutton.

9. As an article of manufacture, a latching device adapted for rigid attachment to the upper end of the molded insulating base of a pushbutton switch of the reciprocating contactor type, said device comprising a one-piece molded insulating member having a passage extending therethrough to provide reciprocating clearance for the upwardly spring-biased pushbutton of the switch, said member having a second passage extending therethrough in spaced parallel relation to said first passage, a flat, punched sheet metal latch member slidably mounted upon the lower surface of said insulating member, spring means normally biasing said latch member for movement into said rst mentioned passage, manual means for eecting movement of said latch member out of said rst mentioned passage, said manual means comprising a pushbutton reciprocable within said second mentioned passage, and a bell-crank lever pivotally supported upon said insulating member and affording a driving connection between said last mentioned pushbutton and said latch member.

10. As an article of manufacture, a latching device adapted for rigid attachment to the upper end of the molded insulating base of a pushbutton switch of the reciprocating contactor type, said device comprising a one-piece molded insulating member having a passage extending therethrough to provide reciprocating clearance for the upwardly spring-biased pushbutton of" the switch, said member having a second passage extending therethrough 'in spaced parallel relation to said ilrst passage, a iiat, punched sheet metal latch member slidably mounted upon the lower surface of said insulating member, spring means normally biasing said latch member for movement into said rst mentioned passage, manual means for eecting movement. of said latch member out of said iirst mentioned passage, said manual means comprising a pushbutton reciprocable within said second mentioned passage, a bell-crank lever pivotally supported upon said insulating member and aiTording a driving connection between said last mentioned pushbutton and said latch member, said latch member being adapted to coact with the switch pushbutton when depressed to retain the latter in depressed position, said second pushbutton when depressed being adapted to eiect release of the switch pushbutton, and said switch pushbutton when released coacting with said latch member to retain said second pushbutton in its depressed position.

ll. In a device of the character described, in combination, a pushbutton switch of the reciprocating contactor type comprising, acne-piece molded insulating base having a recess, a onepiece molded insulating plunger slidable within said recess, a, pair of stationary contacts positioned within said recess, a contactor carried by said plunger and movable by the latter into and out of .bridging engagement with said pair of contacts, a coiled compression spring interposed between the bottom wall of said recess and said plunger to bias the latter toward a given normal position, a pushbutton attached to the outer end of said plunger, said pushbutton having a peripheral groove formed therein to provide an upwardly facing shoulder at a predetermined distance from the lower end thereof, a one-piece molded insulating member rigidly attached to the upper end of said base, said insulating member having a passage extending therethrough to afford reciprocating clearance for said pushbutton, said insulating member having a second passage extending therethrough, a pushbutton reciprocable within said second passage, a nat, punched sheet metal latch member slidab-ly interposed between the lower surface of said insulating member and the upper surface of said base, a pivoted bell-crank lever one arm of which has a driving connection with said latch member and the other arm of which has a driving connection with said second pushbutton, a coiled torsion spring biasing said second pushbutton upwardly whereby said latch member is biased toward a position wherein it overlies said shoulder in the lower extreme position of said .first pushbutton to retain the latter in such position, and said second pushbutton when depressed against the bias of said torsion spring being adapted to withdraw said latch to release said first pushbutton for movement to its upper extreme position.

12. In a device of the character described, in

combination, a pushbutton switch of the reciprocating contactor type comprising, a one-piece molded insulating base having a recess, a onepiece molded insulating plunger slidable within said recess, a pair of stationary contacts positioned Within said recess, a contactor carried by said plunger and movable by the latter into and out of bridging engagement with said pair of contacts, a coiled compression spring interposed be tween the bottom wall of said recess and said plunger to bias the latter toward a given normal position, a pushbutton attached to the outer end of said plunger, said pushbutton having a peripheral groove formed therein to provide an upwardly facing shoulder at a predetermined distance from the lower end thereof, a one-piece molded insulating member rigidly attached to the upper end of said base, said insulating member having a passage extending therethrough to afford reciprocating clearance for said pushbutton, said insulating member having a second passage extending therethrough, a pushbutton reciprocable within said second passage, a ilat, punched sheet metal latch member slidably interposed between the lower surface of `said insulating member and the upper surface of said base, a pivoted bell-crank lever one arm of which has a driving connection with said latch membex` and the other arm of which has a driving connection with said second pushbutton, a coiled torsion spring biasing said second pushbutton upwardly whereby said latch member is biased toward a position wherein it overlies said shoulder in the lower extreme position of said first l0 pushbutton to retain the latter in such position.

said second pushbutton when depressed against the bias or said torsion spring being adapted to Withdraw said latch to release said first pushbutton for movement to its upper extreme position,

l5 said passages in said insulating member having screw threads formed therein by the molding operation, and a pair of hollow metal bushings having peripheral anges at the -upper ends thereof, the lower .end portions of said bushings 20 being externally threaded for cooperative engagement with the threaded walls of said passages.

CLYDE F. ROBBINS. 

